Performance aspects of Paracoccus pantotrophus treating urban solid waste leachate

Abstract

Municipal landfill leachate remains one of the most challenging substrates to be biologically processed. This is the first study to report the behaviour of a mixotrophic bacterium Paracoccus pantotrophus which can simultaneously remove carbon and nitrogen. Both synthetic media and leachate have been used as substrate. Different leachate fractions, i.e. 0, 10, 20, 30, 40 and 50% were investigated. Total initial COD was 1,000 mg/L, which was reduced to 106–204 mg/L as leachate fraction varied from 0 to 50%. Removal of nitrogen was 20–38%. Inhibitory effects of the leachate on the microbial growth and substrate utilization were observed from the maximum microbial growth and sustenance of the biomass. Sustenance of the biomass which was estimated using duration of the stationary phase varied from 124 to 25 h as leachate fraction varied from 0 to 50%. COD levels in all the reactors containing leachate started to increase after 150 h. Such increase continually increased with higher leachate fractions. It indicates the cell lyses and the release of secondary metabolites in the system. These data could be profitably used in a better understanding of the overall process kinetics.

Keywords:

• Batch reactor
• Landfill leachate
• Microbial growth
• Paracoccus pantotrophus

Acknowledgements

This research study was supported by All India Council of Technical Education (AICTE).

Notes

Third International Congress Smallwat11—Wastewater in Small Communities 25–28 April 2011, Seville, Spain